1. Field of the Invention
The invention relates to arc welding equipment and more particularly to rotatable arc welding equipment for performing automatic arc welding operations for forming annular welds using a consumable electrode wire, and in which cooling fluid is supplied to various portions of the equipment.
2. Description of the Prior Art
There are numerous types, styles and arrangements of welding equipment and tools for automatically performing welding operations on a workpiece, including equipment for performing automatic annular welds.
Certain welding operations, depending upon the material to be joined and the nature of the final product, are more suitable for use with a non-consumable electrode, known as TIG welding. Examples of welding equipment for forming annular welds using such a non-consumable electrode are shown and described in U.S. Pat. Nos. 2,908,805, 3,159,734, 3,350,537, 3,513,286 and 3,780,257. These welder constructions are satisfactory for their intended use and are not confronted with the problem of the supply weld wire wrapping around or being movable with the electrode as it rotates, as is present when using consumable electrode wire.
It is desirable for most automatic welding equipment which is used in continuous production welding, to be provided with cooling fluid at the electrode tip, electrical commutator area, and certain rotating portions of the equipment. This cooling enables the equipment to be run continuously for extended periods of time without generating excess heat, which heat is uncomfortable to the operator and harmful to the welding equipment.
The providing of cooling fluid to welding equipment using a consumable electrode together with the components for the electrode feed wire supply means, heretofore, has increased the complexity and cost of such welding equipment. Prior automatic welding equipment using a consumable electrode weld wire has required mounting the weld wire spool on the machine, such as shown in U.S. Pat. No. 3,215,812 wherein the spool rotates with the welding tip. This arrangement enables large spools of wire to be used (in excess of several hundred pounds) reducing continuous replacement of the wire supply reel. Such equipment, however, must be large and more costly than is desirable for many applications in order to rotatably support the large wire reels.
Other types of welding equipment using a consumable electrode weld wire are hand-held and manually operated, such as shown in U.S. Pat. No. 3,114,830 and Reissue U.S. Pat. No. 26,800. The wire supply for these types of equipment is mounted either on the welder itself in small spools (several pounds only) or is fed from a remote stationary reel to the weld tip. Those constructions using the remotely located reels, present problems to the operator who must continually be cautious to avoid tangling the electrode wire as it moves with the welding tip about the axis of rotation. Such hand-held welders, likewise, are difficult to provide with sufficient cooling fluid, in that the supply lines are cumbersome and add to the difficulty of use and weight of the welder. These hand-held welders also are more costly than desirable, in that sufficient safeguards must be incorporated therein to protect the operator, and to sustain the shocks and repeated handling and movement due to their manual operation.
No known welder construction of which I am aware provides a relatively simple construction which combines the advantages of both hand-held and fixed automatic welding equipment for use in forming annular welds, which use consumable electrode wire supplied from large stationary supply reels in combination with cooling supply means to cool various portions of the welding equipment.